1. Field of the Invention
This invention relates to used oil filters and, more particularly, to a novel process for cleaning used oil filters so that the oil filters can be disposed of properly or, preferably, recycled into steel with the residual oil therein having been previously recovered and the wash water recycled through the novel cleaning process of this invention.
2. The Prior Art
An oil filter, as the name implies, is a device for removing particulate matter from a circulating lubrication oil to preclude the particulate matter from eroding the mechanical surfaces being lubricated by the oil. An oil filter is particularly important, for example, in the internal combustion engine of an automobile since the travel of an automobile exposes the bearing surfaces of the engine to numerous sources of potentially damaging particulate matter. The purpose of the oil filter, therefore, is to remove and trap all particulate matter above a certain microscopic size range. It is recommended that the oil filter for each automobile should be replaced every 3,000 to 6,000 miles of travel, depending upon the particular driving conditions for that automobile.
Customarily, the oil filter is changed each time the oil is drained and replaced with fresh oil. The used oil filter is drained of a substantial portion of the residual oil and then discarded. However, the disposal of used oil filters represents a significant waste disposal problem since even the small amount of residual oil will contaminate the soil and ground water in a landfill. Also many bearing surfaces are fabricated from a babbitt metal which includes tin, antimony, and copper so that the natural wear of these surfaces will release these metals and others such as chrome, etc., into the lubricating oil.
Given the millions of automobiles in the United States alone, one can readily determine that there are many millions of oil filters discarded annually. The recycled oil filter should be processed back into steel in a steel-making furnace if the problem of residual oil can be solved. Metal recyclers will not accept used oil filters since the oil filters contain residual oil and residual metal contaminants in both the oil and on the filter medium. Further, the presence of the filter media itself also imposes extra burden on the recycling system.
In view of the foregoing, it would be an advancement in the art to provide a process for cleaning used oil filters. It would also be an advancement in the art to provide a water-based process for cleaning used oil filters while recovering the oil cleaned therefrom and recycling the wash water. An even further advancement in the art would be to provide a novel oil filter cleaning process wherein dirt and other debris is recovered without contaminating the cleaning solution. An even further advancement in the art would be to provide a water-based wash system for removing residual oil from used oil filters wherein the wash system is particularly characterized by the absence of significant emulsification of the oil into the wash water. Such a novel process is disclosed and claimed herein.